This application relates to an improvement in guide structure for lift and carry conveyor systems.
In the prior art, so-called lift and carry conveyors are used to move parts along an industrial line. A lift and carry conveyor may move parts from a first machining station along a conveyor path towards a second station where further work is performed on the part. As the conveyed parts move along the factory floor, they are transferred between sequential lift and carry sections. Recently, it has become known in the prior art to turn the parts through a corner to connect two linearly extending sequential lift and carry sections.
For certain types of parts, prior art lift and carry conveyors have used containment rails which guide the parts as they move on the lift and carry conveyors. As shown in prior art FIG. 1, a prior art lift and carry conveyor 20 included fixed supports 22 which hold a part 24. Part 24 may be a connecting arm for a piston having a ring 26 and an arm 28 with a cylindrical surface 29. Ring 26 may be relatively thin in a direction into the paper, such that it must retain the position shown in this figure or it may fall between fixed supports 22.
A prior art lift and carry member 30 has lift surfaces 32 which sequentially engage an under surface of ring 26 and lift part 24 vertically upwardly off of fixed supports 22. Lift and carry member 30 and part 24 are then moved along a conveyor path. Lift and carry member 30 is then returned vertically downwardly, and part 24 is again rested on fixed supports 22 at a downstream location. Lift and carry member 30 returns upstream to its original location at the lowered vertical location. As described and claimed in this application, it should be understood that these movements may be elliptic rather than four distinct linear movements. During this movement, containment rails 34 move with lift and carry member 30 and remain aligned with cylindrical surface 29 and a lower end of arm 28. Containment rails 34 prevent part 24 from becoming misaligned as it moves along the conveyor path.
Problems arise with this type of conveyor system in that during transfer of parts between adjacent lift and carry sections, the containment rails 34 no longer guide the part 24. Thus, the prior art has experienced some difficulty in properly guiding parts as they are moved onto, or off of lift and carry sections.